Method of cleaning screens, filtering fabrics, and the like.



ll N STrfl lrifl MAYNARD J. TRDTT, 0F COLCRADO SPREEEIGS, GOELGRAIDG, ASslGNfiR'z'TO DQRE" cranrnn raacnrnrin'zfcomranr, or natt an; cotoaano. "I

. METHOD OI CLEANIN TG SCREENS, FILTERING-FABRICS, AND'THE"LIKE. ll No Drawing.

To all whom it m ay concern:

. Be it known that I, MAYNaRu J. Tnor'r,

a citizen of the United States of America, residing at Colorado Springs, in the county of El Paso and State of Colorado, have invented certain new and useful Improvements in .Methods ofCleaning Screens, Filtering Fabrics, and the Like, of which the following'is a specification,

My invention relates toa novel method of cleaning screens, filtering fabrics and other similar objects after they have lost all or part of their permeability by the adhesion or precipitationof solids contained .in matter passed through their meshes. I 7

- My process is particularly adapted for use'in cleaning screens of the class employed in sifting comminuted ores and in removing the extraneous matter which adheres to the sides of the permeable leaves through which the valuable solution is forced or drawn in the filtration treatment of goldand silver ore-slimes by cyanid of potassium and other In an apparatus ofthe character used heretofore for removing the adherent matter such as calcium carbonate and calcium sulfate from the cloth sides of the filter leaves, has consisted in washing the latter with dilute hydro-chloric acid (HCl), a process which involves much labor, considerable expense and many other objection able features, chief among which are the imperfect cleaning of the inner surfaces of the cloth sides, the destructive action of the acid on the fabric necessitating frequent renewal,

the reduction in the eiiiciency of the acid- Wash after repeated treatments, the fact 'thatthe acid does not remove deposited calcium sulfate and the difiiculty encountered in places remote from supply houses, inobtaining the large quantities of acid required in the process.

By my improved method of cleaning the filter-leaves, all the, above enumerated objectionable features are effectively obviated, the cloths are thoroughly cleaned in the minimum of time not only of the entire coatings deposited at both the inside and outside surfaces of the cloth sides of the leaves, but also of all matter which has lodged or precipitated in the interstices of the fabric.

' Specification of Letters Eatent. 1 Application filed August 4, 1911.

Serial No. 642,389.

injure the vfabric but supc essfullyrestoresit touts original COI1d1tlOn,,-Wltl10ut impair,-

ing fabrios', are obtained in cleaning the screens made of woven Wire orfother mate- :rlal, used in stamp-mills, Cl'ulianmills and other apparatus employed in the treatment of comminuted ores, as it will ettectivelyre move the adherent matter. from both sides.

of the screens withoutttheirbeing removed from then frames or from their position in l atente d Pea -4,1913,

from the'leaf-frames, does in ;no',[way1 the mill with which they are Connected, a

feature which is of particular advantageas in most mills of this class, one side of the screens is inaccessible for cleaning purposes.

My improved method of cleaning the screens ,or filtering fabrics consists in sub ecting the surface thereof to the combined concussive and abrasive actions ofa mass of hard-granular material, such as sand, comminuted quartz and the like which is violently projected against said surface either by mechanical means of by the use of air under compression, steam or other motive fluid.

In the cleaning of filter-leaves only the outer surfaces of the cloth sides thereof are subjected to the action of the abradant and by the judicious selection of a material of suitable hardness and size and by properly regulating the force with which it is projected against the leaves, only the heavy exterior coating of the latter is entirely penetrated, but little of the material is forced through the cloth, and-the lighter matter adhering to the inner surfaces of the sides of the leaves as well as that lodged in the interstices thereof, is removed princithe frequent renewals and repairs tit-present required in the operation of the apparatus in which the screens and leaves are employed.

To obtain the most satisfactory results in the practice of my process in cleaning filter leaves, the latter should be thoroughly driedbefore being subjected to the actionof the abradant, for the purpose of rendering the coatings of slime and lime brittle and thereby expediting the removal thereof.

It should be clearly understood that the statements contained in the foregoing description of my process are not merely theoretical or speculative, but are based upon carefully. conducted experiments and practical demonstrations continuously carried on during a considerable period of time with screens and filtering fabrics of apparatus in actual use. 1

Having thus described my improved method of cleaning screens, filtering fabrics and the like and having pointed out the advantages derived in the practice thereof, What I claim and desire to secure by Letters-Patent is z I 1. The method of removing adherent matter from filtering leaves consisting in first drying the leaves to render the coatings action of a granular solid abradant violently projected against the surface thereof;

In testimony whereof I have aiiixed my signature in presence of two Witnesses.

' MAYNARD J. TROTT.

Witnesses:

A. L. BLOMFIELD, C. W. ANKENY. 

